How do I solve inequalities like $||x|-3|\geq0$?

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As the title says, how do I solve inequalities like $||x|-3|\geq0$?

P.S. If the question seems invalid please correct me.

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Your example is always true since the absolute value function outputs always non-negative numbers.

As a training example, consider $$||x|-3|=2.$$ When is it equal to $2$? When the argument of the absolute value is $2$ or $-2$. $$|x|-2=2 \lor |x|-3=-2.$$ For the first equation move $-2$ to the right side. Then ask yourself: when is $|x|=4$? Now you should be able to answer that and then solve the other equation. The set of all possible values of x includes all of the deduced answers along the way.

For inequalities, to solve $|x| > a$ the argument must be greater than $a$ or smaller than $a$. To solve $|x|<a$ the argument must be smaller than $a$ and also greater than $-a$.